Valve spring question

A

Andy

Well-known member
I am still working on my 59AB. I have installed a Isky Max1 cam and Isky lifters. I have the 185-G springs and at the suggested installed heigth, they seem extra strong. I am thinking of installing them without the shims and that would have a seat pressure of 70 lbs or so. They are at 85lbs with the suggested shims.
I have as set of springs removed from an old built engine. They have 9 1/2 coils and the wire dia. is .1535. The Isky springs have 8 1/2 coils and wire dia of .1615.
Maybe the old springs are stock springs or old performance springs. I have no way of knowing. The cam is a billet piece.
The engine is a 3 5/16 x 4 and has been ported and has a wcfb and Eldebrock heads.
I am not racing this engine. I see no reason for heavy spring pressure.
Valve float will not hit a piston!
I sure would like comments on this. Thanks!!!!
 
In a flathead, you don't need excessive spring pressure. After all, gravity helps seat the valves! I've always understood that 60 or so pounds was adequate for most applications. There are several regular posters on the Fordbarn who can give you better, specific recommendations. FWIW. Good luck with your project.
 
There isn't any reason to have more then 50-55 lbs. stock springs with a .060" spacer usually works well. The L-100 in the hydro engine turns 5500 on 60 lbs and it's been doing it for the past6 years.
 
If you don't mind would you please list the recommended installed height of the 185G springs with shims and without and resultant seat pressure of each???

Thanks in advance!

Jim
 
The installled height of a vaolve spring is determined by the distance between the guide and the valve spring retainer. Thus dependine on the valve stem length and the guide location. In most cases this is around 2" +/- something. Now make up a spacer of the same length (Piece of threaded rod and a coupla nuts) . Put a bathroom scale on your drill press (If you don't have one you have the wring hobby). Not place your spring on the threded rod and bring it down on the scale. When the rod hits the scale thats is the installed pressure. If it's too much you have the wrong springs. If not enough add a few spacers.. To get #55 lbs with Chevy valves takes 3 .060" shims with stock valves two shims. There are very few cams on the market today that need more in a street engine unless you're running a 400jr or one of the Potvin cams they need alittle more .
 
I talked to Joe Abbin yesterday about the 185G springs. He suggested they have a seat pressure of 85 #s @ 2.000" installed height and 70 #'s @ 2.050". Seems like a large difference in pressure for a small change in length. Might be more critical than I imagined.

Jim
 
I took Ol' Rons advice!!! I took a spring from the old engine and put it on the scale and loaded it with the drill press. At 2.00" heigth, it had 60# pressure. This required one .060 shim. The 185-G Isky springs had 90# at this heigth. I am going to use the old springs and the one shim. One more worry down the road.
I still would like to know if the springs are Zepher or some other non stock springs. The old engine was built way back as it had block letter Edelbrock pistons. They were ruined by a blotched balancing attempt. The cam is a billet piece but no markings at all. It has the flat end to the lobes like in the old Isky 5 cycle decals. The lift is less than the Max-1 but the duration seems the same. It is completely machined so I don't think it is a regrind.
 
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